'Emergency mode' to keep cellphones running in a crisis

作者：堵怒 发布时间：2019-03-08 12:16:02

By Paul Marks Your cellphone battery running low is an inconvenience at the best of times, but during an emergency, it can be a matter of life or death. A new patent application from engineers at Apple suggests how cellphones could help every last volt in the battery be put to good use when a person makes an emergency call. Getting a phone to recognise an emergency call being made is easy, based on the number dialled: for example 911 in the US, or 999 in the UK. But the next step is more subtle. Apple’s engineers suggest the phone could respond by making it harder for user to accidentally end the call by pressing the wrong button, something more likely in a stressful situation. That can be achieved by requiring confirmation after the hang up button is pressed rather than just ending the call. A second trick can have a significant impact on battery life, the patent application claims. Modern phones are essentially small computers running power-hungry high-speed microprocessors, bright displays, and high bandwidth radio chips. “The resulting higher consumption of battery power may lead to an earlier shutdown of the mobile phone,” says the patent application. It goes on to suggest that, when an emergency call is made, a phone should halt all processes unrelated to the maintenance of the call, putting them into an “idle” mode. Those two features would ensure emergency calls last as long as possible, providing more information for emergency responders, or later forensic investigators. The patent makes a third suggestion, for situations in which the person making a call cannot speak, perhaps due to a medical problem, such as asthma, or because they are fighting off an attacker. Pressing a single button sends a pre-recorded message detailing a person’s medical condition. Another button can be used to have a speech synthesiser read out the user’s location, using the phone’s GPS function – the only piece of hardware not powered down during an emergency call. Technology is one thing, but common sense helps. A spokeswoman for the London Ambulance Service says their operators do their level best to minimise the risk of a loss of emergency communication by ensuring that the first fact they ask a 999 caller for is their address or street location. “Then if we lose them before we get details of the problem we send an ambulance anyway,